Shear zones - an introduction

Part of "The Shear Zone" video channel. This is part of a collection of videos on structural geology within the channel. To see the full range of topics, visit the main channel page. This video looks at the structure of shear zones - the ductile equivalent of faults. The video covers some basic ideas on their kinematics. These are developed in the associated video on quantification of shear strain profiles (check out the Structural Geology playlist).

[@appliedstratigraphix6844]

This is unbelievably good! I wish I had this resource back in college about 20 years ago! You have a gift for breaking down complex ideas, thank you for uploading these.

[@soroush6788]

Thanks Rob. this video was very useful for me to find out finally how the shear zone is.

[@robbutler2095]

thanks - glad you found this useful.

[@clezysiki9311]

Thank you so much. Appreciate this

[@robbutler2095]

Glad the channel is useful for you

[@rajinder2662]

Very good slides.

[@user-ij3qo6xl9s]

I think 45 degrees (αf) may not be always true. The congugate angle 2αf should be random, sometimes 110degrees in middle to lower crust, then less than 90 degrees in most shallow crust, according to quartzofeldspar rocks.

[@robbutler2095]

Hi - not so - this is basic geometry for simple shear. Of course rocks can deform in different ways but then it isn't ideal simple shear. There are of course lots of studies - in naturally deformed rocks, in numerical simulations and in theory that deal with general shear - but simple shear (the game for "Ramsay & Graham" shear zone0s is defined as in the video.

[@user-ij3qo6xl9s]

@@robbutler2095 Thanks a lot. Your talk makes me understand that simple shear is the principle mechanism for shear zones of different levels. Maybe what I talk is just in line with a pure shear environment or Anderson model.